Salamanders are important vertebrate model organisms in several areas of human health and disease research, including spinal cord and limb regeneration, post-embryonic development, toxicology, vision, olfaction, heart development, renal function, and neural transmission. We initiated the Salamander Genome Project (SGP) to develop the first genomic and bioinformatic resources for research using ambystomatid salamanders. During the last grant period, we created the first comprehensive amphibian genetic map, several annotated molecular databases, a community web-portal (www.ambystoma.org), and identified a large number of unique sequences that correspond to different genes in the Ambystoma genome. We propose three Specific Aims to further increase the utility of salamanders in biomedical research. First, we will increase the number of genes identified from Ambystoma mexicanum whose functions are known in humans. This will increase the number of probes for molecular studies, microarray analysis, and gene mapping. More generally, it will allow a greater amount of genetic and genomic information to be cross- referenced from salamander to other vertebrate model organisms (Zebrafish, Xenopus, Chick, Mouse, Rat, Human, etc). Second, we will design a microarray gene chip and use it to identify genes that are differentially expressed during natural spinal cord regeneration and thyroid hormone induced metamorphosis. To better enable the research community, we will make the microarray design freely available. This aim will provide a powerful new tool for salamander researchers and a means for non-salamander researchers to rapidly screen the salamander for candidate genes and gene networks. Third, we will develop a large interspecific mapping panel and use it to identify markers and candidate genes for important A. mexicanum mutants and the sex- determining locus. Gene markers will increase the efficiency of managing a federally funded laboratory stock that provides salamander material to researchers from around the world. With respect to longer-term goals, the proposed project will spur development of additional resources that will facilitate identification of salamander genes of biomedical significance.